Radio platforms are becoming increasingly complex, with multiple radios and antennas often found in a single solution. For example, solutions that require antenna radiation and reception diversity will often utilize two or more antennas, each oriented in a different plane relative to one another. For example, the Nintendo® Wii™ (trademarks of Nintendo of America Inc.) gaming console implements reception diversity using two antennas oriented in different planes.
Such solutions, however, require the use of separate antennas which take up considerable space and are thus generally undesirable. Although for products like the Wii™ there may be sufficient room in the console, small form factor devices, such as, for example, mobile phones, personal digital assistants (PDAs), wireless email devices, etc., simply cannot afford the space to accommodate multiple antennas. For example, platforms currently under development may have as many as 12 active radio solutions, each with individual corresponding antennas. Including additional antennas for MIMO (multiple-input multiple-output) applications, it becomes increasingly difficult to pack such a large quantity of antennas onto, for example, a standard FR-4 (flame resistant 4) printed circuit board (PCB) (FR-4 is a composite of a resin epoxy reinforced with a woven fiberglass mat). Another recently proposed solution involves electronically tuning an antenna using variable capacitors. Here, however, a resonant frequency of a radiating element of the antenna is changed but not a radiating angle of the antenna. Consequently, this technique cannot be used to steer an antenna.
Accordingly, there exists a need for an antenna which does not suffer from one or more of the above-noted problems exhibited by conventional antennas.